/*
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
 */
package com.opensource.dbhelp.dbutils.handlers;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Map;

import com.opensource.dbhelp.dbutils.ResultSetHandler;
import com.opensource.dbhelp.dbutils.StringRowProcessor;

/**
 * <code>ResultSetHandler</code> implementation that converts the first <code>ResultSet</code> row into a <code>Map</code>. This class is thread safe.
 * 
 * @see com.opensource.dbhelp.dbutils.ResultSetHandler
 */
public class StringMapHandler implements ResultSetHandler<Map<String, String>> {

	/**
	 * The StringRowProcessor implementation to use when converting rows into Maps.
	 */
	private final StringRowProcessor convert;

	/**
	 * Creates a new instance of MapHandler using a <code>BasicStringRowProcessor</code> for conversion.
	 */
	public StringMapHandler() {
		this(StringArrayHandler.ROW_PROCESSOR);
	}

	/**
	 * Creates a new instance of MapHandler.
	 * 
	 * @param convert
	 *            The <code>StringRowProcessor</code> implementation to use when converting rows into Maps.
	 */
	public StringMapHandler(StringRowProcessor convert) {
		super();
		this.convert = convert;
	}

	/**
	 * Converts the first row in the <code>ResultSet</code> into a <code>Map</code>.
	 * 
	 * @return A <code>Map</code> with the values from the first row or <code>null</code> if there are no rows in the <code>ResultSet</code>.
	 * @throws java.sql.SQLException
	 *             if a database access error occurs
	 * @see com.opensource.dbhelp.dbutils.ResultSetHandler#handle(java.sql.ResultSet)
	 */
	@Override
	public Map<String, String> handle(ResultSet rs) throws SQLException {
		return rs.next() ? this.convert.toMap(rs) : null;
	}

}
